You can select a datasource which supplies a list of an entity to the widget by selecting a retrieve by Xpath (database) or a microflow in which you make a custom retrieve.
Then you’ll have to configure what the labels in the dropdown selection should say by filling in the display template. By default this is static text but you can add the content of an attribute to it by setting template attributes and entering it as a varibale in the display template text like this screenshot.
Please follow below steps tab wise on bootstrap multi-select widget configuration pop-up,
1. Data Source:
a. Retrieve Type: Choose what is the source be it X-Path or Microflow. based on your choice the next tabs will be configured. Let's take source as 'Microflow'
b. Multi Select Source: This has to be an association on which your multi selections will be stored for further processing. You can create an association on the entity which you want to show on this widget drop-down.
c. Display Template: from below point (d), the template attributes to be chosen in the format you want to display in the widget drop-down.
d. Template Attribute: Here you can choose the attributes of the entity to be placed and shown in the drop-down.
2. Data Source - XPath: This has to be set if chosen data source is 'XPath' in 1.a. Here you need to set the XPath on which the objects are to be retrieved which you want to show in the widget drop-down.
3. Data Source - Microflow: This has to be set if chosen data source is 'Microflow' in 1.a.
Retrieve microflow: A microflow which returns a list of objects which you want to show in the drop-down widget. you can do manipulations and as per your business requirement which object you want to put in the drop-down.
4. Display: you can do the RnD on this.
5. Events: This is where you can set microflows for on-change action.
For example on select of any object from the drop-down if you want to load any report or dashboard then that can be done here by use of a microflow.
I hope, this answers your query.