Greetings from Syncfusion support.
We have analyzed your requirement for select and unselect. By default, the selected item will get deselected during click, it is the usual behavior of chip component. We would like to let you know that, EJ2 ButtonGroup component will meet your exact requirement. Since, the group button has single selection and multi selection mode. During single selection, minimum one value is maintained in selected state (as like radio button group). In MultiSelection mode, you will be able to select more than one value (as like checkbox group).
To know more about the ButtonGroup, refer the below link.
Please let us know, if you have any concerns.