Just in case any reader needs to do something similar with
MS Excel 365.
First, turn the source data into an Excel Table and Name it (
e.g. tblStaff).
That makes references dynamic and independent of the actual positioning of the Table on the Sheet.
The formula is then
= FILTER( tblStaff, tblStaff[STATUS]="AVAILABLE" )
The formula is only placed in a single cell 'availableStaff' but it spills to provide the required records.
If one then needed to know the departments with staff availability one could reference the new range 'availableStaff#'
= UNIQUE( XLOOKUP( "DEPARTMENT", tblStaff[#Headers], availableStaff# ) )
I am so thankful that I need not develop traditional spreadsheets anymore!