Using a qMultiSelector you can filter the data from a selector based on previous selection.
I have 2 lists, Countries(CountryID, CountryName) and Languages (LanguageID, LanguageName, CountryID).
I use a qMultiSelector with 2 selectors, first selector to display the Countries and the second selector to display the languages spoken in the country I select.
On the languages selector you need to use the properties Parent Field Name (set to CountryID) and Filter Field Name (set to CountryID).
Create these 2 lists in your env, add some data and use the following configuration in the qMultiSelector Configuration property.
One important thing I want to mention is that you need to set the property Refresh Page When Selection Change to true (checked) so the data is being refreshed while you change selections.
I'd suggest you to read the docuemntation related to qMultiSelector and if you still have questions please let me know.
<PersistentSelector Title="1st" SiteUrl="." ListName="Countries" SessionName="SessionCountry" DisplayFieldName="CountryID" EmptySelectionItemName="-Select One-" EmptyDropDownItemName="<Empty>" DisplayFields="<Fields> <Field Name="CountryID" /> </Fields>" RefreshWhenSelectionChanged="true" />
<PersistentSelector SiteUrl="." ListName="Languages" Title="2nd" SessionName="SessionLanguage" DisplayFieldName="LanguageID" EmptySelectionItemName="-Select One-" EmptyDropDownItemName="<Empty>" DisplayFields="<Fields> <Field Name="CountryID" /> <Field Name="LanguageID" /> </Fields>" ParentFilterFieldName="CountryID" FilterFieldName="CountryID" />