Using a multi-select list box to filter a union query (Access 2010)

[LikeADuck]

Hi Everyone,

I know this question has been asked hundreds of times, but I need it explained to me like I'm a 5 year-old (I'm so sorry)!

I have a union query set up to run from a button on a form, and I'd like to filter the results down based on a user making multiple selections (from a field called SBU in a table called PROJECT DATA) in a list box before hitting the Run button.

I understand that using a multi-select list box produces a null value, and that I have to write a bit of code to gather sensible input for a query parameter. I just can't figure out how to do it and would be so grateful for any help that anyone can provide to enable me to get my head around it.

button (BtnRun)
union query (QryBURNDOWN1)
form (FrmBURNDOWN2 Srch)
list box (LstPROJECT_DATA_UNBOUND_SBU)

This is me right now --> :banghead:

 

[moke123]

take a look here https://bytes.com/topic/access/insights/589890-retrieve-values-multi-select-listbox to get you started