How to use placeholders in OData service?

Hello,

I am trying to translate the following sql query to retrieve the data using OData service. I am unable to use the placeholder, Is there a way we can use placeholders in OData request URL?

example:

SQL query: select * from "_SYS_BIC"."sam.portal.views/GET_DISTINCT_VIEWS_FOR_TAG2" ('PLACEHOLDER' = ('$$ip_term$$','cost'))

This query works fine.

So now I created an OData service as:

service { 

      "_SYS_BIC"."sam.portal.views/GET_DISTINCT_VIEWS_FOR_TAG2" as "searchByTags" keys ("VIEW_NAME");

}

and I want to call the service using ajax call. Something like:

  url: getServiceUrl("oData/getDistinctTags.xsodata/searchByTags?$filter=....('PLACEHOLDER'=('$$ip_term$$','"+searchTag+"'))&$format=json"),

Could someone please help me with creating the url syntax where I can use placeholder?

Thanks,

Prab