Hello Sunilkumar,
You will need to attach the Google Earth captured jpg as a raster image and then this raster can be moved to back of the drawing. For this, when you capture the Google Earth image, there is a jpg automatically saved in the folder where is the dgn is placed. In MX, CAD menu, go to "File > Raster Manager", and then in the 'Raster manager' dialog box go to "File > Attach > Raster", and select this jpg image. Make sure the "Place Interactively" is checked mark in the right hand side of the 'Attach Raster Reference' dialog box. Select the corner of the attached mesh and place the raster aligned with the mesh. You can then delete the mesh if you don't have to create a terrain of the mesh.
This raster can then be sent to back using the "Display > Sent to Back" option.
