Go to Catalog > Filters and select Insert to create a filter group. Assign a filter group name (e.g. Color) and add filter name values (e.g. Blue, Red, Yellow).

Go to Catalog > Categories and Edit a category. Under the Data tab add the filters you want to be able to apply to that category (e.g. Color > Blue, Color > Red).

Go to Catalog > Products and Edit a product. Under the Links tab add the filters which apply to the product (e.g. Color > Blue). Apply to as many products as applicable.

Go to Extensions > Modules > Filter. If not installed select Install. Click Edit & then Enabled from option & then Save module.

Go to Design > Layout > Edit Category Page and Set whatever position and sort order you would like. and then save.