The modern, Fluent UI combo box control you can add in PowerApps component libraries doesn't seem to have the Search Text property exposed in the way that the original Combo Box does. It doesn't appear to be referenceable in any way:
For example. if I wanted to create a component that serves up a people picker field and used, as input for the component, the Office365Users.SearchUserV2 method, the combobox in the component set to allow searching isn't emitting the text that's typed into the component.
