First, you can compare employment in the US and abroad in US-headed multinationals (I didn;t bother putting the date range breaks in, as in chart 1 above):
They also have statistics for US employment by US affiliates of foreign-headed MNCs, but annoyingly the years do not all correspond so this looks a little odd when charted:
Even so we can see that foreign companies hire what looks like about half as many people in the US as US MNCs do abroad, and the employment in the US seems to be holding steady after a slight uptick between 1999 and 2002.
Now a couple on sales. Here are US vs foreign sales of US-based MNCs:
Steadily rising, across the board, but look at the relative picture, sales by US Parent as a percentage of the total sales of US MNCs (BEA didn't provide this data so I calculated as USP sales/(USP sales + foreign affiliate sales):
That looks pretty startling doesn't it. But it just means that overall, for US MNCS, foreign sales are growing faster than US sales. That's one reason to be an MNC--expansion to other markets.
Now here are sales by US affiliates of foreign MNCs added in (again with the mismatched years):
A bit of an upward trend until 2009, no surprise there, with an uptick in 2010 but more modest than that of the US MNCs.