I am using QGIS 2.12.2. I am using three vector layers (point, polyline and polygon shapefiles) of the region of interest. Any advice in making the selections from one dataset based on the other dataset? What I am trying to do is to select the features of other two layers based on the one layer in QGIS.
The tools available only allow you to make selections on one vector layer based on one other layer. There are a number of tools which allows you to make selections, just to name a few common ones:
(Vector > Spatial Query)
Select by location
(Vector > Research Tools > Select by location; Processing Toolbox > Select by location)
Select by attribute
(Processing Toolbox > Select by attribute)
If you type "Select" in the Processing Toolbox, you will see additional selection tools: