InfoPath allows us to create data connections and fetch values from any SharePoint list. We can also select which column values we want to select. The data connection will then return all the items within the list, to control which value(s) we want to fetch, we can apply filters.
filters Click on the Dropdown properties and select/add a Data connection. In the Entries field, click the XPath selector button which will enable us to select which column value we want to bind to the dropdown control.
Select the parent node and click on Filter Data… to bring up the filter choices