The list picker option, for multi entity data grids (tables) within Evoke allows you to use the tick select option to alter a list of the same entities in another datasource. For Example (see image right from the Example App) if you have a list of suppliers an a list, for each supplier, of the products they supply (see segments bottom left and right), then you can have a list of products (same entity) in the top segment that will have checkboxes checked for each product related to the selected supplier and you can check/uncheck these to alter the list of associated products for the supplier.

Select the Data Segment that you would like the list picker on. In the "Data Content" section (General Tab) check Act as a list picker and a new "Target List" option will appear.

Use the build button to select a datasource that is the same entity (in this case the entity is Products) e.g. Suppliers.current.Products and this is now the entity that will be controlled by the list check boxes.