Filtering with SearchTerm

Hi all.

I need to adapt coding to a existing Fiori App. This App has the search functionality that of course should be implemented.

Debbuging the ABAP code I can see content of IV_FILTER_STRING with value ( SearchTerm eq 'Hello World' ). URL sent by the browser is :

https://host/sap/opu/odata/sap/TEST_SRV/EntitySet?$skip=0&$top=20&$filter=SearchTerm%20eq%20%27dtbes%27&$inlinecount=allpages

In the search box I just typed 'dtbes'.

Is there any class/method to directly filter et_entityset with those entries that contain word 'dtbes'?

Your help is much appreciated.

Iñigo.