How to merge search results?

[lpknv]

Hello!

I am new to ransack (and also ruby (and) on rails and unfortunately the documentation was not 100% clear to me.

In the ransack docs I found this bit of information which looks like something I need.

In my rails app, I want to search through fields in a model Rentalcontract like firstname, lastname, but also I need a second filter option to sort that search result alphabetically ordered by lastname. How can I achieve this using ransack? Any help is so much appreciated!