In Motive, the Labeling pane can be accessed under the View tab or by clicking icon on the main toolbar.
For more explanation on the labeling workflow, read through the Labeling workflow page.
Labeling pane includes a list of marker labels that are associated with the capture. The color of each label tells whether the marker is tracked in the current frame, and the corresponding gap percentage is indicated next to each label. When a marker set is chosen under the Selected dropdown menu, only associated labels will be listed. In addition, the marker set selection can also be linked to 3D selection in the perspective view pane when the Link to 3D button is enabled.