Yes, you can do it easily in unity. But first, you need to understand Camera, RenderTexture, Canvas, and RawImage in Unity.

Below is step by step procedure to achieve the result you wanted.

1. Create a New Scene
2. Add New Camera using Right Click > Camera
3. Change Camera's Projection to "Orthographic"
4. Select the "Main Camera" which is by default available in New Scene.
5. Change Camera's Clear Flags to Solid Color and change background to "Black" and change projection to "Orthographic"
6. Create RawImage by Right Click > UI > RawImage
7. Now set RawImage Position to the are you want to see ex."Working View"
8. Go to project > Create > New RenderTexture
9. Select the RawImage and Drag the RenderTexture you created to RawImage's Texture property.
10. Drag that RenderTexture into the New Camera's "TargetTexture". (Camera we created manually is New Camera)

I hope this helps!

What actually happens here is we transfer Whatever Render into the new camera to "RenderTexture" and make it render back to scene using RawImage.

Yes, you can do it easily in unity. But first, you need to understand Camera, RenderTexture, Canvas, and RawImage in Unity.

Below is step by step procedure to achieve the result you wanted.

1. Create a New Scene
2. Add New Camera using Right Click > Camera
3. Change Camera's Projection to "Orthographic" (You can skip this step, or set according to your requirement)
4. Select the "Main Camera" which is by default available in New Scene.
5. Change Camera's Clear Flags to Solid Color and change background to "Black" and change projection to "Orthographic"
6. Create RawImage by Right Click > UI > RawImage
7. Now set RawImage Position to the are you want to see ex."Working View"
8. Go to project > Create > New RenderTexture
9. Select the RawImage and Drag the RenderTexture you created to RawImage's Texture property.
10. Drag that RenderTexture into the New Camera's "TargetTexture". (Camera we created manually is New Camera)

I hope this helps!

What actually happens here is we transfer Whatever Render into the new camera to "RenderTexture" and make it render back to the scene using RawImage.