Note: You will need to have at least LiveProject Premium Viewer to use this feature. To use the shared server options, you will need at least LiveProject Team Viewer. Compare versions.
You can zoom on a Resource Usage view by selecting the context sensitive menu Resource Usage Settings > Zoom
Select the desired zoom level for the Resource Usage view.
Switching zoom levels will show the selected duration, scaled to fit the visible area of the Resource Usage view.
While zooming the Timescale may change to fit the window. Similarly, while setting the Timescale, the zoom level may change.