As per my knowledge ,there is no Client side configuration type option to make this default focus change. Default Focus can be changed from the Code level (Application form development)
You can achieve this through a simple customization change through the Consultant team.

-Kelum

Hi Kelum,

Thank you for the reply. Can I know how to set this default focus from code level? we have dev license.

case contact log tab is loaded to Business activity window as dynamic tab page. is there a way to set focus on a dynamically loaded tab page in code level?

Hi @Imalka Bandara,

In Designer.cs file, you just have to change the SelectedIndex value to the tab which you want the application to open up when you open the form window. Let’s say you want to open up the 2nd tab in the form window, 

Then,

this.picTab.SelectedIndex = 1;

Note that the indexes start from 0.

Thank you @Himasha Abeywickrama . I will try this out.