GST registered person needs to show the transaction of another non gst firm transaction also?

As a Sole Proprietor, all incomes will be clubbed together for Income Tax purposes and for determining the Agreegate turnover limits under GST. GST registration number is PAN based.
If two firms are operated under Single PAN with different trade names i.e. A tiles and A transportation...then you can not do like one is Registered under GST and other as unregistered.

You are required to show all your income under GST (both business).

@ Sagar Patel

Thankyou sir, for your valuable suggestion.

my Truck carries Cement, TMT etc. through Transport Agency. Cemet/TMT companies issue GST bill including freight (FOR basis) to their dealers/Customers. Transport agency at the end of month pays me fright after deducting TDS etc.

how should I put these entry in GST portal?