In the attached workbook there is about 5 sheets, i'm using this formula to extract all unique records in column B only in sheet (5) based on a criteria in main!D2
=IFERROR(INDEX('5'!$A$1:$A$2222, SMALL(IF(ISNUMBER(MATCH('5'!$B$1:$B$2222,$D$2, 0)), MATCH(ROW('5'!$B$1:$B$2222)...