Every planet in astrology appears to have a flexible tri-partite nature so that it can accomodate interpretations for various levels of reality.
The Sun, for example, is dignified(at home) in Leo, and should be the most obvious or radiant feature in any chart, but because we do not live on the Sun, it no longer becomes the primary expression in a chart. On any other planet, the Sun, in fact, acquires a Cancerian(Leo's night side) quality, and is often described as one's "inner" or "private" self. The Sun also, because we live on the Libran planet of opposites, takes on the characteristics of its opposing planet, Uranus, which is why the Sun is also an indicator of your "individuality".
In this way, every planet can be identified via its linkage to three signs: its home or ruling sign, its night or day sign(expressed in the traditional rulership scheme), and its aspect sign(in our case-the opposition). The table below will carify this.
This explains why the Moon, normally associated with maternal(Cancerian) characteristics, can also be your popularity(Leo) or your buisness(Capricorn) planet.
Why Mercury, normally associated with cerebral(Geminian) characteristics, can also be your skill(Virgo) or philosophy(Sagittarius) planet.
Why Venus, normally associated with evaluative(Taurean) characteristics, can also be your relationship(Libra) or sex(Scorpio) planet.
Why Mars, normally associated with primordial(Arian) characteristics, can also be your sex(Scorpio) or partnership(Libra) planet.
Why Jupiter, normally associated with spiritual(Sagittarian) characteristics, can also be your psychic(Pisces) or communication(Gemini) planet.
Why Saturn, normally associated with professional (Capricornian) characteristics, can also be your scientific (Aquarius) or home/security (Cancer) planet.
Why Uranus, normally associated with unconventional (Aquarian) characteristics, can also be your career (Capricorn) or inner will (Leo) planet.
Why Neptune, normally associated with mystical (Piscean) characteristics, can also be your religious (Sagittarius) or daily habit (Virgo) planet.
Why Pluto, normally associated with regenerative (Scorpion) characteristics, can also be your pioneer (Aries) or money (Taurus) planet.
Why the Earth/Ascendant, normally associated with relational (Libran) characteristics, can also describe your physical nature or appearance (Taurus) or the initial impression (Aries) you make on others.
The Inner Sun/ Midheaven is still a puzzle to me. It is often linked to one's career or public standing (Capricorn), as well as one of the Parents (Cancer), and one's alter or higher ego (Leo). It is also one's consciousness (Gemini), working capacity (Virgo), and purpose or calling. It is difficult to determine the home sign, if any, although the candidates would certainly be Gemini, Cancer, or Virgo.
This triple nature of the planets demonstrates the flexibility of astrology to accommodate all possible cosmic realities or situations in life and should be noted or considered whenever doing interpretations.