Combine or group different item in one item with same gst percentage

Combine or group different item in one item with same gst percentage

Hi
I am into IT business.
On assembled pc we buy different parts like hdd cpu etc and assemble it.
What I want is, I want to group all such stock into one item (one cpu) and bill it as one item and one price on Invoice.
with this, each items in that group must be deducted by 1.

GST for all this item will be 18% only

So is this possible?