To Add a Tool to a Group or a Panel

Do one of the following:

Select File > Settings > User > Customize Ribbon .

or
Right-click in the blank space in the ribbon and select Customize Ribbon from the pop-up menu.

The Customize Ribbon dialog opens.
In the Customize Ribbon dialog's Ribbon section, select Buttons from the Choose components from drop-down list.
All buttons are listed below Choose components from.

Note: If a button is not listed, then it means that the button is not created. In such case, you can select the Toolboxes (Application) option in the Choose components from drop-down list and search for an existing tool that can be converted to a button. Otherwise, you will have to create a custom tool in the Customize dialog with the desired key-in and other settings. This custom tool would then appear when you select Toolbox (Custom) in the Choose components from drop-down list.
In the list below Customize the Ribbon, navigate to the desired workflow, tab, and the group or panel to which you want to add the tool.
Do one of the following:

From the list below Choose components from, select the desired tool and then click Add.

or
From the list below Choose components from, select and drag the tool to the desired group or panel in the list below Customize the Ribbon.
Click Apply.

Note: For adding tools to a group, if the component source (Choose components from drop-down list) is set to one of the Items to Import type, and if the component selected contains sub-components, then a split button is created. If a tool or button is selected, then just a simple tool is created.