When you have multiple scatter plots of the same VOTable you can select
in one of the plots and select related points in other plots using
this feature.
In the main window, to select points on other plots which are related
to those selected in the Active Plot click the "Select Points
on other plots w.r.t. Active plot" icon 
in the tool box or "Select Points on other plots w.r.t. Active
plot" menu item in the "View" Menu.
The dialog has check boxes for each plot (child window) in the main
window. If a plot is empty corresponding check box is disabled. Active
Plot's check box is disabled and the corresponding label is in blue
color. Select the checkboxes of plots on which you would prefer to
select the points related to those in the Active plot and click "OK".
The dialog is shown in the figure 17 below:
