Custom Share Url for every post

If you have implemented ShareThis manually on your website –
To share the desired content you can use “st” property, for example to share URL you can use “st_url” property
you can know more about it from here: http://support.sharethis.com/customer/portal/articles/475079-share-properties-and-sharing-custom-information

And if you have installed a ShareThis WP Plugin –
You Can use Open Graph Tags to specify the content to be shared. Like to share particular URL you can use “og:url” tag
You can know more about it from here –
http://support.sharethis.com/customer/portal/articles/475079-share-properties-and-sharing-custom-information#Open_Graph_Tags