The easiest way to manipulate listbox content I have found is SQL statements.
Create a query from the table to collect the data you want in your list box. Once this is displaying what you want you can go to SQL view and copy the SQL. Close the query and save it if you want.
Open a new form in design view and select the listbox size it to what you want and open the properties window. to the Row Source property and click on the ... This will take you to a query design grid, go to the SQL view and paste your code in there. Go back to dataview and check your query is still selecting the records you want.
Close out and check your column count, and column width statements, you may need to modify these.
Open the form in form view and it should show your list box. (if a column is too narrow or wide or missing, refer above)
To open this from your save button, just go into code and type DoCmd.OpenForm MyForm, after the save event is complete.