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Advocate II
Advocate II

Lookup relationship between three data sources

Hi Everyone!


Scope is three SharePoint lists:

- Products

- Ingredients (has lookup column Products)

- Frequently asked questions (has two lookup columns Products and Ingredients)

Idea is that one question can be related to multiple products and multiple ingredients at the same time. Users would like to improve their working process when adding new questions to the list, so that they don't have to memorize relationship between products and ingredients. For example, when user edits FAQ form and selects one or more ingredients -> then all related products should auto-populated/pre-selected for him.


So far have tried several formulas with choice fields, but lookup turns out to be more challenging especially because of three list relationship. 


Would like to ask your help and fresh piece of thought on this one.

Any hint is appreciated 🙂

Community Support
Community Support

Hi @ZaneZ ,


My understanding is that you want to know how to set the default selected items of a combo box inside Form control that is a lookup column in SharePoint. If my undestanding is correct, then you should add all 3 lists as data sources in the same app. And set the DefaultSelectedItems property of combo box control to something like below:

        Id: LookUp(ListA, Title = "xxx", ID), 
        Value: "xxx"

This lookup field get the information from ListA's Title field. This formula means that set the default selected items to the "xxx" of ListA. 


More details about setting a default value for a LookUp field in PowerApps, please check the following thread:

Please also check and see if the following blog would help in your scenario:


Best regards,





Community Support Team _ Mona Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

Hi @v-monli-msft ,


Many thanks for your tips! Resources you shared turned out to be really helpful.

This formula now retrieves two values inside combo-box "Product" which is SharePoint lookup column of QuestionAnswer (QA) list.

Filter(Choices(QA.Product),Value = "EXAMPLE SHINE SHAMPOO" Or Value = "EXAMPLE CC CREAM")

Question now is how to make it filter dynamic values?

So that combo-box Product shows all Products that are assigned to selected ingredient.

Relationship between ingredients and products are defined inside Ingredient (INCI) SharePoint list. Combo-boxes are located inside QA list form. Hope that makes sense.


Did came up with formula which shows all Products assigned to selected ingredient -> which is exactly as needed, but...

LookUp(INCI,'Ingredient Name' in DataCardValue5.Selected.Value,FoundIn)

...problem here is that it works only inside empty comb-box which is outside SharePoint connector Form. When pasted inside the combo-box Product it gives error "The function LookUp has some invalid arguments". 


Have feeling that combo-box Product doesn't recognize Ingredient (INCI) list. All three lists have been added as datasources inside PowerApp. 


Any thoughts?





Not applicable

Hi @ZaneZ I'm going to bump this in the hopes some fresh eyes can provide additional insight



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