How can I show from Parental Combobox the valuse from a TableGrid

Hello v_pozidis.
Please find attached your project with changes.
1.  There is a new line in the script.
2.  You only need to set the parent combobox property on frmcreateexample.combobox2;  you do not set it on form1.combobox2.
Hope this helps.
Derek.

Hello v_pozidis,
In that case, I suggest you don't use a script at all;  just add a button with 'show record' functionality, double-click the row in your tablegrid and the information (including the correct parent combobox functionality) will be displayed (see attached).
Derek.

If I understand you correctly, I think you now want to add/change/delete records using only form1?
If so, look at the attachment (there are other ways).
You still do not need a script to get the parent combobox functionality to work - that is fixed simply by adding a 'show record' button, as I explained earlier.
However, I have added a small script to hide the 'save' button, unless you are in 'new record' or 'show record' mode.  I do this to stop duplicate rows being accidently created - something which can easily happen when you try to do everything on just one form.  But it is just a safeguard;  strictly speaking, you do not need this script either.
Maybe this is what you want now.
Derek.