HI there,
Create your data connection to the list and you can probably set it to query on load. Then insert the repeating node in the 2ndary data source as repeating table. This should show all of the data from the list.
To do the search you are talking about, I would recommend using filters. Add a text field, and then go to the properties of the repeating control and filter data. You need to create a filter that looks like if searchField = listColumn and that should only display the rows which match the filter. Alternatively, you can optimize for performance by using queryFields as well. In the 2ndary DC, expand queryFields to see all of the fields in that folder. You can set one of these fields and then query the connection which will then retrieve all the items that match the data you entered.
Hopefully one of those solutions will help guide you to what you need.