I've put data to columns - counted - need dropdown filter
 

I've got a two columns spreadsheet with cells which have more than one set of
data in them. I've put column A from text to columns and managed to count
it, but now need to find out how to add the filter button at the top of the
column which enables me to filter according to number of names i want to see.
It is a name and address spreadsheet but the names and addresses are mixed
up, with some cells containing more than 5 names (column a) and some more
than 5 addresses (column b). i've sorted column a, but cannot find a unique
separator for column b.

please help me!!!