Hi, 2 parameters are dependent when one takes the the other parameter as its input.
For example, if you want to take profit/sales cut off as a parameter and also per year as another parameter then the final decision depends on the 2 previous parameters.
You can add a parameter as an input to parameter from the create parameter dialog box. So the parameter 2 depends on parameter 1.
You can make a parameter dependent by set from parameter option.
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2 parameters can also be dependent when both are used in any field to perform any operations.
Hope this helps you.
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