Caml Query filter lookup field which have same values

Hi Experts,

Currently, I have a case, in my list, I have a list which have a lookup field, this field is looking up to another specific field, The looked up field have some duplicated same values.

Now I want to filter the lookup field, how to get the specific one ?

For example, The lookup field have 2 "Test" Value, I want the second one, not the first.