The toolbars can be easily moved (to rearrange, or undock for a floating toolbox): click and hold the handle on the left end of the toolbar, then drag.
The drag handle is a vertical marker on the left end of the toolbar (I see a dotted line, but other linear vertical designs may be in use).
The drop down list is automatically created on the right end of the toolbar when the available space is too small to accomodate all activated icons.
Apache OO 3.4.1/4.1.2, on Ms Windows 7/10 and Mac OS-X. LibreOffice 18.104.22.168 on Mepis Antix MX