Ok, yes so Search isn't delegable with SharePoint, so once you reach over 2000 rows it will only show 2000 rows and then ignore the rest of the data. Rows 2001 to 5000+ will not be available if you use Search with SharePoint.
Your current formula,
Search(BRD,TextInput1.Text,"Title","Scope","BusinessPurpose")
Needs to become This (and you won't be able to do partial search, only where it starts with something) :
Filter(
BRD,
//if nothing is typed in the search then don't filter,
Len(TextInput1.Text)=0
//otherwise filter for items starting with:
||
(
StartsWith(Title, TextInput1.Text)
||
StartsWith(Scope, TextInput1.Text)
||
StartsWith(BusinessPurpose, TextInput1.Text)
)
)
Cheers,
Sancho