I would like to have a button to take the values of two reference selectors and a drop-down.
Pengyuan (Jeremy) Chen
If I understand what you're trying to do, you would like to select a JobFamily and/or JobSubFamily and find all the Jobs that have one or both of those. You can build that in the Page you included in your posting as follows:
In the microflow called by the Search button, the first action should Commit the Job object (you should have the Job object as a parameter for the microflow)
The next step is to do a retrieve of the JobFamily and the JobSubFamily from the Job object (because you committed the Job, the values of these 2 references are now available for you to retrieve)
Now you can retrieve a list of Jobs whose JobFamily and JobSubFamily is the same as the Job object you passed in to the microflow. You'll need to use an XPath retrieve to get this list of Jobs - so that you can use the values you retrieved.
As you probably already know, this type of retrieve is also available using native Search fields on a datagrid or templategrid. There are also some really good search widgets in the app store that you may want to explore - Data Grid Search Filters is one that I use often.