Dependent option for multiple Parent

I’ve a usecase where in I’ve a two select field source and medium. Source is a parent field and medium is dependent field on source.

The values/options that medium field will display is based on select option of source field.

In my use case it is n to n mapping which means options of medium field will display on selection of multiple source.

Sources could be Google, FB, Quora, Yahoo, etc
Medium could be - CPC, CPL, Email, A, B, C

Now I want medium field to display select option CPC, Email and C when source field is any of Google or Quora.

How can I achieve this without creating Multiple Fields, Doctype or Custom Script. Can I create condition in field or what will be script for ‘Depends Upon’