I use this formula to concat after I use the auto filter:

=SUBSTITUTE(MCONCAT(IF(SUBTOTAL(3;OFFSET(E5:E1074; ROW(E5:E1074)-MIN(ROW(E5:E1074));;1));";"&E5:E1074;""));":";"";1 )

My data looks like so:

AM
AM
AM
AE
AE
AE
AB
AB
AB
AB
AB
AB

For example, if I filter down to "AB", the formula gives me the following
result:

;AB;AB;AB;AB;AB;AB

Is there a way to modify the formula to only show me the unique value, in
this example

AB;