Not sure when you mean Norman, and please note this is definitely NOT my subject of "expertise", but according to the table in this reference, in 1935 "Yorkley Court" was a detached part of Newland Parish, as was nearby Badhamsfield.
see https://www.british-history.ac.uk/vch/glos/vol5/pp195-231

The above text, under Newland, includes the following mentions of Yorkley, there may well be more...

"Of the detached parts of Newland lying east of Clearwell tithing, Whitemead, evidently inclosed by the Crown itself, was recorded in 1283. Land at Bream had been cleared and settled by the mid 14th century, and there was farmland at Ellwood by the same period. In 1282 the meadow of Yorkley was mentioned, and in 1310 land in the Yorkley area was held by John ap Adam, whose name is presumably preserved in that of Badhamsfield farm. An assart of 36a at Yorkley was mentioned in 1338."

"The two detached portions further east at Yorkley were also sandwiched between Lydney parish and the Forest and were divided from each other by a strip of roadside waste along the Lydney to Yorkley village road. The western portion, comprising the Yorkley Court estate, covered 281a and the eastern one, comprising Badhamsfield farm, 77a. Collectively the three portions at Bream and Yorkley formed the tithing of Bream."

"The detached parts of Newland at Yorkley, divided by the road running north from Lydney to Yorkley village, probably had dwellings by the early 14th century. Seven cottages mentioned on Lord Berkeley's manor of Yorkley in 1346 may, however, have been in Lydney parish, from which the manor received rents. In the early modern period the parts of Newland at Yorkley appear to have contained only two farmhouses, Yorkley Court in the west part and Badhamsfield in the east part. Badhamsfield, as mentioned above, probably derives its name from medieval ownership by the ap Adam family and the farmhouse was recorded by that name in 1626, but the surviving house is no earlier than the late 18th century and was heavily restored in the mid 20th. By 1775 c10 cottages had been built on parish land at the north-west boundary of Yorkley Court farm as part of the developing village of Yorkley. In the mid 19th century land within the parish was colonized by a larger group of cottages called Yorkley Wood."

"In 1901 the population of Newland civil parish was 1,877, rising to 2,061 by 1931. In 1951, after the loss of the parts at Bream and Yorkley, the population of the civil parish was 1,148, declining to 877 by 1971 and rising again to 924 by 1991."

"A manor called YORKLEY, presumably based on the two detached parts of Newland there, belonged by 1346 to Thomas, Lord Berkeley, who died in 1361. It may have included land owned in 1310 by John ap Adam, whose nearby Purton manor passed to the Berkeleys. Lands in the Yorkley area later belonged to the Clearwell estate: in 1481 John and Joan Barre conveyed a house and 100a at Yorkley to Thomas Wall, and other lands, described as at Lydney, Gorsty field (in the east of the detached part of Newland at Bream), and Badhamsfield (presumably land once of the ap Adams) to Thomas Kedgwin. The western detached part at Yorkley later comprised Yorkley Court farm, which belonged by 1693 to the ironmaster Thomas Foley (d 1737), passing to his son Thomas and grandson Thomas (d 1777), Lord Foley. Lord Foley's estates in the Forest area were sold soon after his death, and in 1806 and 1821 Yorkley Court belonged to Thomas Packer. By 1840 it belonged to Samuel Cholditch, whose family still owned the farm in 1910. In 1992, then c190a, it was owned and farmed by Mrs A J McBride. There were farm buildings, including a dovecot, and probably a dwelling on Lord Berkeley's manor in 1346. The farmhouse at Yorkley Court was rebuilt in the early 19th century."

This map shows the two detached areas quite well.

https://maps.nls.uk/geo/explore/#zoom=15&lat=51.7533&lon=-2.5299&layers=178...

(Open in new tab)

--
Peter

On older 1800's maps of around the top of Plump Hill, there are areas designated something like "Newland ex-parochial", which I take to mean that it came under Newland parochial Church, as the Forest was Crown Land at the time. I stand to be corrected here as I am doing this from memory only.