VBA Extract unique values depending on selected item in another column

In the attached spreadsheet there are two columns of data. the first contains locations (cities) the second column has cost centres. Cost centres can be found in more than one location (& vice versa).
Using VBA:
1) I would like to give the user the option of selecting a location (using a dropdown or combo?),
2) from this selction an output is automatically created listing the cost centres that can be found in this location. However each cost centre should only be listed once. For example cost centre 1234 can be found 3times in London but this only needs to be listed once as per output starting at cell E5.

Has to be VBA rather than advanced filter as it's part of a larger search tool.

Many thanks in anticipation

See if the attached works for you

Thank you, that works perfectly - now just need to incorporate this into the main workbook!