The Software

• Is intended to simplify exporting current project families as .rfa files to independent content libraries.
• Exported families are sorted in subfolders by category.
• Features overwrite control, list filters and sorting functions.
• Displays preview images and useful family data.
• Could be docked in the work area.
• This software is developed and tested in Autodesk® Revit® 2021 on Windows 10, 64-bit only. 

The Interface

The Topmost is the info area. This area holds a preview image field and a data field which are populated when selecting items from the family list. Note: the preview image could be empty.
This area also holds a checkbox labeled Overwrite which allows you to decide beforehand if existing target files should be overwritten. If left unchecked, you will get an additional popup warning if the exported file(s) already exists.

Next is the list view area consisting of three list views, filter boxes and flip and flyout buttons.
Checking category list items will narrow the number of items in the family list. Category list settings are stored between sessions.
The family list reflects category list selection and can be further narrowed by using the family list column filter boxes.
The type list is not initially populated but will display selected family symbol types.
The flyout button is intended to collapse or expand the category list and the flip button should be used if you like to reverse the position of the category list.
The list separator lines could be used to change the individual size of the lists.

Initially, all category list items are unchecked, and the family list shows all families in the project. As you start checking categories in the category list, the family list will change to reflect your selection. Next time you return to the tool the category list will continue where you left off.

Following is the path selection area.
The leftmost (red circular arrow) button is intended to refresh all the lists. Use this button if you have added new content to your project and you suspect that it is not visible in the list.
The label displays the currently active export path. Mouse right-click on the label will open a new Windows Explorer in that location. This is convenient when you should verify the export.
The path select button opens the folder browser dialog.

The export button. The button is normally disabled but will be enabled if valid items are checked in the family list, and a valid export path is found.