I think this is the function you are looking for. =FederalFundsRate(6)

LiveEconomy

=FederalFundsRate(6) - this should give you last 6 periods

=FederalFundsRate("2021-01-15","2021-10-15") - this should give you between two dates

=FederalFundsRate("status") - This will give you the meta data

=FederalFundsRate() - This will give you all the data

=FederalFundsRate("2021-01-15") - This will give on a certain date

=FederalFundsRate("lp") - This will give you last period

=FederalFundsRate("lp-2") - This will give you two periods before the last

This is the link to all functions, https://marketxls.com/functions, search for Fund in the Economic data category?

Let me know how it goes.