Display Data based on Selected Value from Drop Down List

Hi Everyone,

I hope you're well and staying sane at these unique times. I'm in need of some help and i think the thing im looking to do needs to be done via VBA or via a Macro, to which i wont have a clue how to do so I'm in need of some help with this please.

Take a look at the attached file, you will see 4 worksheets which are:

MainData - This is where all the data is coming from.
Summary - This is the output and the main worksheet ill be working from and includes formulas to get data from the MainData worksheet.
Wholesalers - This will have the account numbers and the name of the wholesalers they use (notice how the same account may use more than 1 wholesaler)
UniqueWholesalerList - This is a unique list of wholesalers used for the Wholesaler drop down list on the Summary worksheet.

What I'm wanting to do is for the worksheet Summary to only show accounts that have the selected Wholesaler selected from the drop down list. Any help on this would be greatly appreciated.

If you've any questions please ask.

Thank you in advance!

Edit: Apologies if this can be done using Formulas, if it can I'd rather it be so i can learn more formula stuff and i apologise if that's the root this thread goes down since its in the wrong forum.