Below logic is working for me, if there is a better approach please do let me know.
If(
IsBlank(LookUp(NUA_online_Test_repository, Delegated.Email = Blank())), Filter(
NUA_online_Test_repository,
Status = "Documented" || Status = "Awaiting Reply",
'Internal Use' = "Application Specific" || 'Internal Use' = Blank(),
Retain = "Retain" || Retain = Blank(),
'Documented on'< DateAdd(Today(),-730,Days),
'Application Manager'.Email = User().Email
) ,
Filter(
NUA_online_Test_repository,
Status = "Documented" || Status = "Awaiting Reply",
'Internal Use' = "Application Specific" || 'Internal Use' = Blank(),
Retain = "Retain" || Retain = Blank(),
'Documented on'< DateAdd(Today(),-730,Days),
Delegated.Email = User().Email
)
)