Enable JavaScript in the browser to display LibreOfficeDev Help pages.
Align Vertical Center
Vertically centers the selected objects. If only one object is selected in Draw or Impress, the center of the object is aligned to the vertical center of the page.
From the menu bar:
Choose .
From the tabbed interface:
Choose (text selected).
From the sidebar:
Select - deck.
To align the individual objects in a group, choose Format - Group - Enter Group
double-click to enter the group, select the objects, right-click, and then choose an alignment option.