I have a log, containing 4 columns. First 2 columns contain dept name and
team name respectively. Third column contains a timestamp at which the row
was added to the spreadsheet. By design, we always add a row at the end of
the existing list (thus an append, never an insert between existing rows).
The 4th column contains a value.

My need is that if I give a dept and team name combination (via 2 cells), I
would like to have the value of the 4th column returned for the
chronologically last entry in the list for the dept + team combination. WE
DO NOT NEED TO CONSULT THE TIMESTAMP COL, it can be assumed that records are
always added in chronological order and thus the last record with the DEPT +
TEAM combination is what I am looking for.

any ideas on how to do this without writing a macro?

Many thanks in anticipation.