hi @Jibin
Thank you for your post to MS Q&A !
As I understand, you want to use--
a) same domain name dev.contoso.com >> 2 ASEs in 2 different subnets under 2 different subscriptions
b) If App1 is deployed in ASE1,then app1.dev.contoso.com, similarly App2 in ASE2 then app2.dev.contoso.com.
Yes, this can be achieved.
You would need to add App G/W in your design. Additionally, you would need plan to work on the LB (internal or external depending of your app requirements), gateway / route tables a bit to achieve this.
Please refer as starting point-
https://learn.microsoft.com/en-us/azure/app-service/environment/using-an-ase
https://learn.microsoft.com/en-us/azure/app-service/environment/integrate-with-application-gateway
Let me know how it goes.
(Please don’t forget to **"Accept the answer" & “up-vote” **, this can be beneficial to other members. Thank You)
Regards, ** J.D. **