After another listen I can confirm that the eyewitness 'Grant' describes watching a funeral, or rather an actual burial, in the church graveyard from his young daughter's bedroom window.
Disconcerted, he walked round to the graveyard for a closer look and found nobody there and no trace of a funeral.
There were many other incidents. It's a cracking tale, though the stress of the haunting and its apparent cause sadly helped break up Grant's marriage.
Having enjoyed the episode and especially appreciating the precision of the locations mentioned I looked the place up at the time.
It's not hard to find.
Here's the area on Maps -
Tudor Close on Dean Court Road, Rottingdean
All the locations are easily seen, including
the bench.
Here is an advert for the sale of the house in 2021. Have a look, it's stunning.
(safe local newspaper link)
Brighton house which inspired the Cluedo board game on the market
No mention of the ghost though.
Finally, I offer a safe Higgypop page on the history of the complex in the context of the BBC Uncanny episode.
Full of spoilers so maybe better read after hearing the episode with its first-hand eyewitness accounts. 'Grant' really does describe it all beautifully.
The History Of Tudor Close The Haunted Former Hotel Featured In 'Uncanny'
Here's about the only non-spoiling quote I could find -