This article provides the steps for creating a dynamic title in Power BI reports.
Table title = "Enrollment for " & SELECTEDVALUE(Term[TERM_DESCRIPTION],"Multiple Terms")
You will see "Multiple Terms" on the tile when you select multiple terms now.
Table title = "Enrollment for " & IF ( ISFILTERED ( Term[TERM_DESCRIPTION] ), CONCATENATEX ( FILTERS ( Term[TERM_DESCRIPTION] ), Term[TERM_DESCRIPTION], " & " ), "all terms" )
You will see this:
Table title = "Enrollment for " & IF ( NOT ISFILTERED ( Term[TERM_DESCRIPTION] ), "all terms", SELECTEDVALUE ( Term[TERM_DESCRIPTION], "multiple terms" ) )