It si sipmle, because I know what I want. It went wrong because I was
not able to achieve this.

First table I have is table products with filds:
group (text)
subgroup (text)
katalog number (text)
name (text)
description (text)
price (number)
image (container)
note (text)

LinkID1 (calculation=group & subgroup) >>added later
LinkID2 (calculation=group & subgroup & katalog number)>>added later

From this table I created layout in list view as product catalog:

in this layout I created several buttons with scripts. Purpose was to
click on button called group one and he will listed all products from
selected group. This was not an issue. I added also field choose.
Purpose was to setup this field as button (checkbox or radio button).
Idea was to click on record in within catalog, and selected records
will be displayed in new table called offer. I was not able to create
either script or calculation.

Second table I created is called offer.
I have following fields in it:
group (text)
subgroup (text)
katalog number (text)
name (text)
price (number)
quantity (number)
discount (number)
price with discount (number)
total (number)

field repetittion is set to 20

sum (number)
vat (number)
total (number)

After I was not able to create script in product catalog, I tried following:
fields
group (text)
subgroup (text)
katalog number (text)
name (text)
are copied from table products. I define relationship
table product>offer group=group. Above mentioned fields have been
defined as dropdown list>value list (use valeus from
field)>tableroducts::group. Same value lists are created for subgroup
and katalog number.
What I want from this is following:
click on group and select group
click on subgroup and see only subgroups related to choosen group
click on katalog number and see only records from choosen group and
subgroup. However, everything I tried was not succesfull.

If you look at the fields created in table products, you see fields like
LinkID1 and LinkID2. I tried in table offer to implement field LinkID1
instead of group and subgroup. This will narrow my search for products
from selected group and subgroup. When I did everything, inlcuding
defining value fileds, I was suprised to find out I can not use
calculaton fiels for selection.

I tried a lot of different things, but I end up with getting all results
from selection group.
group>subgroup>katalog number.

My goal is following
click on group and select group
click on subgroup and see only subgroups related to choosen group
click on katalog number and see only records from choosen group and
subgroup.

How to achieve this?