This is called a conditional value list. Here are some links on the subject:
There's a lot of overlap between the first two links so you can read one and skim the other. The demo file gives you several examples of different conditional value lists so you can examine them to see how they are set up. If you are using FileMaker 12, you can open this demo file from your File menu to get a converted copy of the demo file that you can examine in FileMaker 12.
The last link discusses how to set up a chain of conditional value lists where the value selected in each conditional value list controls the values listed in the next value list.
Forum Tutorial: Custom Value List?
Knowledgebase article: http://help.filemaker.com/app/answers/detail/a_id/5833/kw/conditional%20value%20list
Hierarchical Conditional Value lists: Conditional Value List Question
Feel free to post follow up questions here if those links aren't enough to get your value lists working correctly.
can I also set a default value (refer to example "Knowledgebase article") for the categorie, say to be used in different layouts?
Yes, but please explain what you want in more detail so I can tell you how.
I understand the previous question was too general. So here is a good example:
Say I have an extensive address table with a 'type' field with the values of "customers" , "clients", "suppliers".
I want to use the individual subsets for different purposes. For instance, if I want to assign resources to a client, I'd like to use one 'assignment' layout . In that layout I call up the resource, say manpower, and I asign it from a picklist of only the customer names.
As far as I have now learned (literally) is that I would have to have a two step approach, first selecting from the 'type' field the value "customer" and then in an addressfield, pick the name from a now limited customer list.
I set a default value in the first 'type' field, which still required to click on the field, so I couldn't hide the first selection process in the layout, thus making it unvisible to the user.
I seems an obvious option for fmp to have, and as previously, I do not know the keyword, under which I would find the relevant information.
I gather each layout specifies a different category?
1) Use a script trigger performed by OnLayoutEnter to set the value in the first field. (Which then serves as the match field in the relationship that controls the conditional value list.) This match field can have global storage specified.
2) Use an unstored calculaiton field. The calculation can have an expression such as:
Case ( Get ( LayoutName ) = "Customer List" ; "Customer" ;
Get ( LayoutName ) = "and so forth...
I have a similar need but feel it is simpler. I have a database for the purpose of registering exhibitors in horse show classes. I need to keep a list of the horses in order to check vaccination records to report to the state. I have a table of horses with their pertinent data. On my exhibitor list ("contacts") there is a field for "horse" to choose a horse from the "horses" table. I have a relationship set up so that the "horse" field in the contact table is related to the horse field in the horses table, and a pop-up field on the contacts layout to pick the horse. So far, in order to populate the list in the pop-up menu, I have to have the relationship set up to "allow creation of records in this table via this relationship" in both sides of the relationship. As such, by choosing a horse in the pop-up menu on the contacts layout, the horse is added to the horses table, even though it already exists. I want each horse listed once and to be able to pick a listed horse for the displayed contact without duplicating the horse. Some riders have to share a horse (not in the same class, of course). I tried to use the concept in the example above with the restaurant menu and orders, but probably lost my place and it didn't work. Thanks.