Explanation:

Box 1: Access control: Grant
The users in Group1 must be prompted for multi-factor authentication (MFA) when they connect to Azure Virtual Desktop.
Create a Conditional Access policy (see step 15 below).
Here's how to create a Conditional Access policy that requires multi-factor authentication when connecting to Azure Virtual Desktop:
1. Sign in to the Azure portal as a global administrator, security administrator, or Conditional Access administrator.
2. In the search bar, type Azure Active Directory and select the matching service entry.
3. Browse to Security > Conditional Access.
4. Select New policy > Create new policy.
5. Give your policy a name. We recommend that organizations create a meaningful standard for the names of their policies.
6. Under Assignments, select Users or workload entities.
7. Under the Include tab, select Select users and groups and tick Users and groups. On the right, search for and choose the group that contains your Azure Virtual Desktop users as group members.
8. Select Select.
9. Under Assignments, select Cloud apps or actions.
10. Under the Include tab, select Select apps.
11. On the right, select one of the following apps based on which version of Azure Virtual Desktop you're using. If you're using Azure Virtual Desktop (based on Azure Resource Manager), you can configure MFA on two different apps:
* Azure Virtual Desktop (app ID 9cdead84-a844-4324-93f2-b2e6bb768d07), which applies when the user subscribes to a feed and authenticates to the Azure Virtual Desktop Gateway during a connection.
* Microsoft Remote Desktop
If you're using Azure Virtual Desktop (classic), choose these apps:
Windows Virtual Desktop (app ID 5a0aa725-4958-4b0c-80a9-34562e23f3b7) Windows Virtual Desktop Client (app ID fa4345a4-a730-4230-84a8-7d9651b86739), which will let you set policies on the web client.
12. Once you've selected your app, select Select.
13. Under Assignments, select Conditions > Client apps. On the right, for Configure, select Yes, and then select the client apps this policy will apply to
14. Once you've selected the client apps this policy will apply to, select Done.
15. Under Assignments, select Access controls > Grant, select Grant access, Require multi-factor authentication, and then select Select.
16. At the bottom of the page, set Enable policy to On and select Create.
Box 2: Access controls: Session
The users in Group2 must reauthenticate every eight hours while they are connected to Azure Virtual Desktop.
Configure sign-in frequency
To optionally configure the time period before a user is asked to sign-in again:
1. Open the policy you created previously.
2. Under Assignments, select Access controls > Session. On the right, select Sign-in frequency. Set the value for the time period before a user is asked to sign-in again, and then select Select. For example, setting the value to 1 and the unit to Hours, will require multi-factor authentication if a connection is launched over an hour after the last one.
3. At the bottom of the page, under Enable policy select Save.