How do I populate a userform combobox with fields from a pivot table?

[ajmhouser]

I have been searching for over a week online and haven't found anything that works. I have a userform that has 3 combo boxes ( Provider, Year, & Quarter). When the user chooses what they need it will filter the data from the pivot table so they can print a report. At this time I haven't managed to populate the userform comboboxes with the pivot table fields and am stumped as to what code would work. This is my first exploration into VBA so please let me know what to get started with. I have tried putting the fields I want to filter in column section and filter section and couldn't get to work. From another suggestion I put the sections I want in the filtered sections then renamed the cell they were in on the pivot table and that didn't work for me either.