Due to popular demand, this functionality was added to Primavera P6 v15.1.
For Primavera P6 version 15.1 and later:

1. When Exporting a Project from Primavera P6 Professional (File, Export), select the 'Primavera P6 XML' format.



 The option to include Baselines in an XER Export is not available in Primavera P6 15.1.

2. To include a Baseline, click in the 'Baseline to Export' column.



3. Check the 'Export' option for the Projects you wish to Export.



4. Click OK and complete the Export.

For Primavera P6 versions 8.4 and earlier:

For Primavera P6 8.4, you will need to follow this workaround to Export the live Project and Baseline Project separately:

1. Prior to Exporting the Project, detach the Baseline from the live Project, and Export both Projects separately. Remember to re-attach the Baseline after the Export:

a. Open the Project.

b. Go to Project, Assign Project Baselines. un-assign the Baseline that needs to be Exported.

c. Go to Project, Maintain Baselines. Select the Baseline and click 'Restore'. This will detach the Baseline so that it is now a standalone Project in the EPS.

d. Export both the Baseline Project and the Live Project via XER or XML formats (File, Export).

e. Re-attach the Baseline Projects by opening the 'Live Project' and closing the 'Baseline Project'.

f. Go to Project, Maintain Baselines.

g. Click 'Add', and select 'Convert another Project to a new Baseline of the current Project'.

h. Select the the 'Baseline Project'. This will re-attach the Baseline to the live Project.

i. Go to Project, Assign Project Baselines. Re-assign the references to the Baseline.

2. When Importing, Import both Projects separately, and once both have been Imported, attach the Baseline Project to the live Project.

a. Open the 'Live Project' and close the 'Baseline Project'.

b. Go to Project, Maintain Baselines.

c. Click 'Add', and select 'Convert another Project to a new Baseline of the current Project'.

d. Select the the 'Baseline Project'. This will attach the Baseline to the live Project.

e. Go to Project, Assign Project Baselines. Assign the references to the Baseline.