How can I select the hidden lines and snap on the same?Solution:
SELECTING THE HIDDEN LINES
1. Go to File > Settings > User > Preferences and check if it Input category the locate interior is set as Visible or Always. If not, set it as one of these options.
2. Back to your drawing, navigate yourself to the hidden line which you want to select/snap.
3. Hover over on this hidden line and press right mouse button. The lines should be highlighted
4. To select the highlighted line, press the left mouse button.
SNAPPING TO THE HIDDEN LINES
1. Repeat the steps 1 and 2 described above.
2. Select the tool (e.g. Place SmartLine tool).
3. Hover over on this hidden line and press left and right mouse buttons together. Probably you should press these buttons more than once to select the hidden line. The amount of pressing depends, how many elements is hidden.
4. Note that the selected snap will affect where you press.