There are many things that can cause this issue. Unfortunately, your photo did not come through, so I cannot assess the damage.
Mostly, overwatering, or disease will cause this. Junipers have few problems, but insects and disease from wet soils can take one down, pretty fast.
If you suspect diseased or wet soils, you could try a fungicide. This article will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
Junipers will appreciate drier soils. They don't tolerate wet feet, very well. Make sure that you do not water this tree. Even in drought, they can stand up with little to no harm, so less is more, here.
Here is an article that will help you to care for the shrub:
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/care-of-junipers.htm
Is there any chance it will recover ?
This is unfortunate, and usually due to disease. While some shrubs are disease resistant, this can vary from plant to plant.
You cannot save this tree. You will need to remove it and treat the spot. After treatment, you can replant.
Here are some articles that will help:
https://www.gardeningknowhow.com/ornamental/trees/tgen/sudden-tree-death-causes.htm
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/juniper-twig-blight-disease.htm
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
My sea green juniper shrub is quite large now, and very healthy. I wonder if I could dig it up carefully and divide it in half by cutting through the root ball.
Examine the stems first and see if any are separate. If not, I would hesitate to cut it in half. They do tolerate pruning, if you aren't happy with the height or width.
I recently purchased two Bonzai Japanese Junipers and was to they should winter outside. I live in the Chicago area and it is late February and the soil is frozen. How do I treat these Junipers for inside storage? I am new to this Bonzai growing.
You do not want to care for these, indoors. They need a cold winter period to perform properly. They must be wintered outdoors. I would heed the advice given, and winter them outside.
Here are some articles that will help:
https://www.gardeningknowhow.com/houseplants/bonsai/first-bonsai.htm
https://www.gardeningknowhow.com/houseplants/bonsai/bonsai-soil-requirements.htm
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/japanese-juniper-care.htm
I need to move my juniper ground cover to a new area how do I do this?
Sure! Here are some articles to help you do so, successfully:
https://www.gardeningknowhow.com/garden-how-to/info/relocate-plants-safely.htm
https://www.gardeningknowhow.com/ornamental/shrubs/shgen/best-times-for-transplanting.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/transplanting-trees.htm
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/growing-creeping-junipers.htm
I search for one i can grow in 5000ft elev northern Nevada. Need to block neighbor view and if it makes Berries that's wonderful.
Here is info about junipers that should help:
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/care-of-junipers.htm
Blue Point Juniper - up to 12 feet
Blue Arrow Juniper - up to 15 feet, columnar
Soft Serve False Cypress - 6 feet
Hinoyki Cypress - 10-12 feet
Here are taller evergreens:
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/zone-5-evergreen-trees.htm
I would like to use the berries to flavor a gin
It is not listed as one of the safe cultivars for use. The berries may contain unsafe levels of thujone, which will be unsafe for consumption.
This article will go over some of the more common edible Juniper berries:
https://www.gardeningknowhow.com/ornamental/shrubs/juniper/are-all-juniper-berries-edible.htm