You have two types of groups in ServiceDesk Plus Cloud application say, Static and Dynamic. Add to group option in asset list view page is to group bulk of assets. These assets will be grouped under the Static group by default.
To add IT Assets to a group,
Go to Assets and click IT on the left panel.
Choose any one of the IT Assets from the drop-down box e.g. Access points, printers, etc. This opens the particular IT asset page.
Select the assets to be added to the group by enabling the checkbox. Click Actions >> Add to Group. The Add Asset(s) to Group window pops up.
By default, you can group assets only to the static group. Either to the Existing static group or New static group can be added.

If you would like to group the assets under existing static group then click the corresponding radio button. Select the Group Name from the combo box.
Else, if you would like to add a new static group and group the assets, click New Group radio button. Specify the Group Name and relevant information about the group in the Description field.
Click the Save button to save the changes.