Re: Display different Power BI dashboards on Power apps Portal based on window size
HI @PowerappsUser06 ,
Could you please share a bit more about your scenario?
Do you want to display different Power BI Dashboard in your Portal screen based on the window size?
Regarding the needs that you mentioned, I think the Liquid expression in Portal could achieve your needs. I have made a test on my side, please try the following workaround:

Go to your Portal Designer, then find the screen which you want to display your Power BI Dashboard. Click "Source Code Editor" in bottom of your designer screen. Then Type the following formula:
{% assign pagesize = settings['page size'] | integer | default: 10 %}
{% if pagesize > 10 %}
{% powerbi authentication_type:"powerbiembedded" path:"https://app.powerbi.com/groups/d624c984-9194-404b-9a0b-33cca3d88c6b/reports/c71d64d8-f61d-43bf-ab3b-f35a116ee4cb/ReportSection1" %}
{% elsif pagesize > 5 and pagesize <= 10 %}
{% powerbi authentication_type:"powerbiembedded" path:"https://app.powerbi.com/groups/d624c984-9194-404b-9a0b-33cca3d88c6b/reports/c71d64d8-f61d-43bf-ab3b-f35a116ee4cb/ReportSection2" %}
{% else %}
{% powerbi authentication_type:"powerbiembedded" path:"https://app.powerbi.com/groups/d624c984-9194-404b-9a0b-33cca3d88c6b/reports/c71d64d8-f61d-43bf-ab3b-f35a116ee4cb/ReportSection3" %}
{% endif %}
Please consider use the powerbi liquid tag to embed your Power BI Dashboard into your Portal screen, please check the following article:
https://docs.microsoft.com/en-us/powerapps/maker/portals/liquid/portals-entity-tags#powerbi
Please try above solution, then check if the issue is solved.
Regards,